On the comparison of different magnetic field models for a selection of exoplanet-hosting astrospheres

Project Description:

Over the last decade or so, quite a few Earth-like, potentially habitable exoplanets have been discovered. These planets are often found orbiting extremely close to their (often active) host stars, significantly closer than Earth to the Sun. The question thus naturally arises as to what influence stellar energetic particle (StEP) radiation would have on their potential habitability. This has lead to many studies attempting to model their transport in a wide variety of astrospheres. It has been shown, however, that assumptions made as to the astrospheric magnetic field, which plays a significant role in the transport of these particles, can greatly influence the conclusions of these studies. A standard approach is to use the Parker model for the AMF, but this, while being valid for the Sun's heliosphere, may not be appropriate for the large array of often very different exoplanet-hosting astrospheres, especially for those with extremely fast stellar winds. In these scenarios, the Weber & Davis model may be more applicable. The aim of this study is to compare the Parker and Weber & Davis magnetic field models for already-published plasma parameters corresponding to those found for a variety of astrospheres, in order to see whether the latter model would indeed yield results greatly different to those predicted by the Parker model. The influence of the Weber & Davis field on the magnetic focusing of StEPs will also be considered, to provide preliminary insights into potential effects on the transport of StEPs.

Research Area:

Space Physics

Project Level:

Honours

This Project Is Offered At The Following Node(s):

(NWU)

Special Requirements:

A good mathematical background.